The present invention relates to a vehicle with a drive motor and a refrigeration circuit.
Vehicle air conditioning units are always designed with “crash safety” in mind. One aspect to be taken into account is that, in the case of a crash where refrigerant lines or individual components of the refrigerant circuit are damaged, no or as little as possible refrigerant should escape into the passenger compartment.
The object of the invention is to create a vehicle with a refrigerant circuit of relatively high safety with respect to the safety aspects described above.
This and other objects are achieved by a vehicle with a drive motor and a refrigeration circuit. The refrigerant circuit, when viewed in a refrigerant flow direction, has a compressor, a gas cooler or condenser, an expansion device and an evaporator, wherein the refrigerant circuit has a first shutoff element arranged outside of an area that is located between the drive motor and the evaporator.
The starting point of the invention is a vehicle with a drive motor and a refrigerant circuit. The drive motor can be disposed in an engine compartment in front of a passenger cell (vehicle with front engine). Alternately, the drive motor could also be arranged in an engine compartment behind the passenger compartment (vehicle with rear engine).
When viewed in the direction of flow of the refrigerant, the refrigerant circuit has a compressor, a gas cooler, an expansion device and an evaporator.
An aspect of the invention is that the refrigerant circuit has a first shutoff element, which closes in case of a crash of the vehicle if the refrigerant circuit is damaged (such as, for example, a tear in a refrigerant line, destruction of a component of the refrigerant circuit, or the like). In accordance with the invention, the first shutoff element is arranged in an area of the vehicle where the probability of the first shutoff element being damaged in a crash and becoming inoperative is relatively low. In accordance with the invention, the first shutoff element is arranged outside of an area located between the drive motor and the evaporator.
In a vehicle with a front engine, the evaporator—when viewed in the driving direction of the vehicle—is arranged behind the drive motor. The evaporator—when viewed in the driving direction of the vehicle—is commonly arranged behind a firewall that separates the passenger compartment and the engine compartment of the vehicle. The evaporator is commonly disposed in a so-called air conditioning device which, in a vehicle with rear drive, is arranged in the area of the center tunnel above the transmission bell housing.
In the event that the evaporator or a refrigerant line located in the passenger compartment becomes damaged in a crash, the first shutoff element closes and limits the amount of refrigerant flowing out through the leak and/or the damaged evaporator into the passenger compartment.
As already indicated above, in accordance with the invention, a “forbidden area” is defined, which could also be called a “critical area.” The term “forbidden area” is understood to be an area into which the drive motor could be pushed in case of a more severe crash of the vehicle.
In accordance with the invention, the first shutoff element, which is to limit the escaping amount of refrigerant in case of damage to the refrigerant circuit, is arranged outside of the “forbidden area”, which is to say in an area that is particularly crash-safe, which is to say in an area where the probability that the first shutoff element would be damaged in its function during a crash of the vehicle is relatively low.
According to an aspect of the invention, the first shutoff element is a check valve that allows the refrigerant to pass through in the common direction of flow of the refrigerant circuit, and shuts off in the opposite direction.
According to another aspect of the invention, the refrigerant circuit has a so-called low pressure filling connector, which when viewed in the direction of flow of the refrigerant is arranged after (downstream of) the first shutoff element. By definition, the low pressure filling connector is arranged on a low-pressure side relative to the expansion device of the refrigerant circuit.
According to a further aspect of the invention, the refrigerant circuit has an accumulator or collector which, when viewed in the direction of flow of the refrigerant, is arranged downstream of the first shutoff element and which, in particular, when viewed in the direction of flow of the refrigerant, is arranged downstream of the low pressure filling connector. Therefore, the task of the first shutoff element is in particular to prevent a back or outflow of refrigerant from the accumulator or collector in the direction of the expansion device if the refrigerant circuit is damaged.
Safety can be improved further with respect to limiting the amount of outflowing refrigerant if a second shutoff element is provided. According to an aspect of the invention, the second shutoff element—when viewed in the direction of flow of the refrigerant—is disposed upstream of the evaporator. In case of a crash where the refrigerant circuit is damaged, the second shutoff element limits or prevents refrigerant from flowing from the high-pressure side of the refrigerant circuit in the direction of the evaporator.
With respect to safety aspects, the second shutoff element is also arranged outside of the “forbidden area”, which is to say, outside of the area between the drive motor and the evaporator.
Preferably, the “forbidden area” includes more than merely the area directly between the combustion motor and the evaporator. For example, it may be provided that the “forbidden area” defines a “projection of the drive motor” in a direction opposite to the driving direction of the vehicle (for a vehicle with front engine) or a projection of the drive motor in the driving direction of the vehicle (for a vehicle with rear engine), wherein the first, as well as the optionally provided second, shutoff element is arranged outside of the potential crash area defined by the projection of the drive motor.
If one wants to improve safety even further, the potential crash area or the forbidden area can be defined even broader. For example, it may be provided that, when viewed in top view of the vehicle, the forbidden area additionally includes a left area, which with a longitudinal direction of the vehicle includes a specified angle, and/or a right area, which with a longitudinal direction of the vehicle includes a specified angle, with the first as well as the optionally provided second shutoff element being arranged outside of the additional left and/or right area. The specified angle may be 45°, for example.
The second shutoff element may take the form of an expansion device that is capable of being shut off, which is to say, the expansion device of the refrigerant circuit can be developed as an expansion device capable of being shut off. Alternately, the second shutoff element may be separate from the expansion device and may be, for example, arranged in particular directly upstream or downstream and/or in particularly directly downstream of the expansion device.
According to an aspect of the invention, the second shutoff element can be electrically triggered, wherein it can be provided that it is open when an electrical voltage is applied to the second shutoff element, or that it is closed if the voltage drops below a specified voltage or if no voltage is applied to the second shutoff element. A second shutoff element designed in this way is failure-proof, which is to say, it shuts off if the electrical voltage drops below a specified voltage. The closing of the second shutoff element can be effected, for example, by a mechanical spring integrated in the second shutoff element.
According to another aspect of the invention, the refrigerant circuit has a high pressure filling connector which, when viewed in the direction of flow of the refrigerant, is arranged downstream of the gas cooler. If the refrigerant circuit has a low pressure filling connector as well as a high pressure filling connector, the refrigerant circuit can be evacuated and filled with refrigerant very well during filling of the refrigerant circuit.
Furthermore, a so-called internal heat exchanger may be provided. A first section of the refrigerant circuit located between the high pressure filling connector and the expansion device may be coupled thermally to a second section of the refrigerant circuit located between the accumulator and the compressor.
With a vehicle having a front engine, the gas cooler, when viewed in the driving direction of the vehicle, may be arranged in front of the drive motor in an engine compartment of the vehicle.
The firewall already mentioned above, which separates the passenger compartment from the engine compartment, preferably has a passage through which a supply line and a return line of the refrigerant circuit runs.
As already mentioned, the first and the optionally provided second shutoff element are arranged outside of the so-called forbidden area. The first and/or the second shutoff element can be, in particular, arranged in a lateral area next to the drive motor.
The invention is particularly suited for so-called CO2 air condition units, which is to say for vehicles with refrigerant circuits through which carbon dioxide flows.
In summary, the invention achieves the following advantages:                The “safety function” of reducing the amount of refrigerant that potentially flows out into the passenger compartment during a crash of the vehicle is ensured even in the event of more severe damage to the vehicle and/or the refrigerant circuit,        The danger of a potentially critical “refrigerant-air-mixture” being created is limited.        
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.